It is well known that an image forming apparatus bills a fee for a print service such as copying and printing when such service is provided.
Another proposed apparatus among these types of image forming apparatus deals with a billing process in a case where job data is received, but an error occurs when image data contained in the received job data is converted to a bitmap (see the specification of Japanese Patent Application Laid-Open No. 2003-256177).
With an image forming apparatus of this kind, however, a problem has arisen when billing for a double-sided printing service if such print service is provided. Specifically, after the completion of printing on one side of a sheet of paper, the following printing operation is suspended without completing printing on the other side, the problem is whether to bill the user for the printing service of the one side. Since the user was expecting printing on both sides, it may be unreasonable for the user to pay compensation even though only single-sided printed matter is obtained. From the standpoint of the billing side, however, since at least the printing of one side was completed and the print service was provided to the user, so that the billing side wishes to bill for the compensation for the single-sided printing. In other words, a conflict can occur between the billing side and the user side when an incomplete service has been provided.
Accordingly, an object of the present invention is to provide an image forming apparatus and method thereof, in which double-sided printing service can be billed appropriately.